I don't think it's actually stored on the Tab, but I could be wrong.
I've dug out my Quick Start Guide: "Accessing more Information"
On your devise open the web browser and select the bookmark for the user manual from the bookmarks list
Visit
www.samsung.com to view devise information, the user manual and more.
The user manual may not be available depending on the web browser or service provider
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I've just checked mine and by opening the "Internet App" and following the instructions above, I'm able to view the manual. At the time of purchase I had actually downloaded the manual to my desktop and printed it off but like you thought it was on the Tab but mine certainly isn't. Hope this helps?